Assignment 2

Question 1

a. A rail overhead mast for an as-constructed survey requires the surveyor to submit a chainage/meterage and radial offset (meant to be 26580 and 3.0m) from the design centre-line (around the curve), to record its position. From the starting point tangent (TS) of 26480m the following angle and distance were observed from the straight, 5o16’30”, 99.83m. The horizontal circular curve has a radius of 800m and curves to the right. (i) Calculate the chainage/meterage based upon an arc length and radial offset from the centre-line for the overhead mast. (This is a typical asconstructed problem solving question, there are no examples in the study book, it could be done by calculation or by CAD, if done by CAD it must be supported by a plan view). (ii) If the compliance is +/- 30mm from 3m for offset and +/- 50mm for chainage/meterage from 26580m. Calculate and state whether the mast meets compliance for offset and chainage/meterage? Fully document your answer.

b. A resection for road construction set-out has been undertaken from an arbitrary position and on an arbitrary datum. The following observations were made to 2 known control points (fully document your answers):

Control point 2 (300.01 E, 600.01N); FL 0° 0’ 0”, FR 180° 00’ 10” 101.086m

Control point 1 (280 E, 400 N); FL 183° 00’ 45”, FR 3° 00’ 45” 99.983m

i. Reduce the readings and calculate the radiation required from the point (on the control line datum) to set-out the road centre-line at 10140m (250.00 E, 460.00 N). 

ii. If the instrument control point has an elevation of RL 100.200m, height of instrument is 1.61m, height of target is 1.525m and the following vertical observations (zenith angle, slope distance) were made remotely to point 440m:

Observations to 440: ZA 89° 20’ 40”, Slope distance 58.00m

Calculate the required constructed pavement layer thickness (loose) if point 440m has a design grade level of 101.100m and there is a bulking factor of 25%.

c. A client has approached you about building a rectangular ring-tank dam to hold a volume of water greater than 4000 m3. The client believes that at depth of 4.0m for a dam base of 35 x 19 metres with 1.5:1 (horizontal to vertical) batters the storage capacity should be within the desired range. Calculate the storage capacity for the dam?

Note: There are a number of different methods and formulae available to compute the task. If you choose to computer model the dam, you must submit a software generated volume calculation report and also a check manual calculation.

Question 2

You are required to develop a preliminary sewer design for a gravity fed pipeline network to service a subdivision development. (i) Provide a plan of your design (to scale or close to scale, I would suggest you blow up to A4 size and work out the scale) including manhole location, stubs, offset distances, house connections etc. and (ii)a discussion of your design and/or any design issues. Assume a 150mm pipe will be sufficient pipe size to drain into M/H2. See below Lot plan (obtain from StudyDesk), no calculations are required, assume the standard lot width is 20m wide for scale purposes (the plan scale will be incorrect because of re-sizing).

Question 3

a. A medium-rise multi-storey building is to be positioned parallel offset to the boundaries of a Lot (say 50m x 25m) and grid lines established along selected building columns inside the building line, see diagram below. The SW corner of the building is to be positioned 1.0m north and 7.5m east of the SW corner of the Lot (the boundary lines are aligned to north and east). The external dimensions of the building are 30.3 m long and 16.3 wide. The building columns are 0.30m square and the external face of the columns abuts the face of the building line. The building column separation (centre column to centre column) are 15m in length and 7.5m in width. An arbitrary plane co-ordinate system is to be established from the SW corner of the Lot (500 East, 700 North) and the grid set-out and labelled as alpha characters north/south and numeric characters east/west i.e. A1, A2 etc. The grid corners are to be set-out 0.800m (both east/west and north/south) from the centre of the building columns as indicated per the diagram.

(i) Calculate the co-ordinates for all grid points.

(ii) List checks you would apply to confirm: calculation of the grid corners; the positioning of the building; and the shape of the building.

(iii) You are required to place six sighthole/penetrations, mark the positions with respect to the grid and/or columns on a sketch/diagram.

b. You have been requested to undertake a ground and feature model survey for a road construction project along an existing road reserve (40m wide). The survey commences at chainage 6,600 mark and is to end at chainage 8,500 mark. The proposed route contains a 200m length of curve from 7,600 to 7,800 and includes a creek requiring a subsequent bridge site at the 7,400 mark. List the chainages where you would be required to place permanent survey marks or benchmarks to meet typical road authority guidelines (as per the study guide). A maximum of eleven benchmarks is allowed, full marks are achieved for the optimum number of benchmarks.